1. Field of the Invention
The invention relates first of all to a method for producing pins, for example, battery terminals, as used in electrical batteries as an anode charge eliminator as well as to a device for performing the method.
2. Description of Related Art
The known methods start with a wire which is first cut into sections, then provided with a head, and transported by being freely suspended in a transport rail to a grinding roller for producing a point at the lower end of the pin. The thus formed pin blank is then transported in the transport rail to a receptacle where the thus machined blanks are collected for further processing.
In the known method burrs are formed at the pin end by the grinding process which make an after processing of the blank necessary. When using the pins as directed in a battery, the burrs at the point of the pin end cause the formation of gas bubbles in the anode substance which causes disturbances. Such burrs also soil the apparatus for processing the pins and also present problems in regard to automatic feeding of the pins.
In the known method the pin blanks are subjected to a further special treatment in order to remove the burrs at the point of the pin. The pin blanks are filled into vibratory grinding devices where they are machined together with chemicals and grinding agents. This requires time-consuming further machining steps and also machines that take up a lot of space thereby making the manufacture of battery terminals more expensive. Furthermore, the after treatment in the vibratory grinding device can result in an undesirable after treatment and wear at the remaining surface areas of the pin because of the grinding agents.
In a method for smoothing an annealed tube, which is to be used as a solid electrolyte in sodium sulfur cells (PATENT ABSTPACTS OF JAPAN, vol. 017, no. 106 M-1375), identical surface areas of the tube, on the one hand, at the end and, on the other hand, on the shaft, are respectively individually treated by two combination rollers. The combination rollers comprise at the same time grinding agents as well as rotating brush means. The rotation axes of the combined rollers extend parallel to the longitudinal axis of the tubes. In both processing steps the axis symmetry and the angle of attack of the grinding and brush means are identical. The piece-by-piece treatment of the tubes by the combination roller is cumbersome and time-consuming. The tubes have no heads so that transport rails cannot be used. Also, at the opposite end of the tubes there are no points to be ground so that a deburring of points is of no concern.
In another method for forming points at rod-shaped objects (DE 41 07 871 A1), a receiving device is used for these rod-shaped objects. The receiving device has an exit opening which is arranged at an acute angle to the end face of the grinding wheel. The removal of burrs is not addressed. The circumferential area of the grinding wheel is not used when treating the rod-shaped objects.
For polishing needle eyes (DE 36 324) the needles are guided between a slowly rotating disk and a hollowed table. A quickly rotating hollowed steel wire brush rounds off the eye and polishes it. The manufacture of the needle points is carried out independently in a separate device. The treatment of the needle point is not suggested in this device.
The invention has first of all the object to develop a reliable method of the kind pursuant to the preamble of claim 1 for producing battery terminals, which method produces battery terminals in a faster and cost-saving manner. This is inventively achieved by the features of the characterizing portion of claim 1 having the following special meaning.
According to the invention, a plurality of rotating pins are simultaneously positioned within different processing stages which are taking place in two sequentially arranged but separate sections of the transport rail. The grinding roller for forming the points of the pin blanks is arranged in the first rail section, while an auxiliary individual roller for deburring the pin points is employed in the second rail section. The pins are positioned within these rail sections and are, depending on their respective position in their individual processing stages. At the beginning section the pins are still blanks or intermediate products while toward the final section they are increasingly nearing completion. At the end of the rail the finish-machined pin end products fall into a common receptacle where they are collected for further processing. Moreover, in both rail sections the engagement angle of the rollers at the pin ends is different. This angle is greater at the roller for deburring that is machining the incoming intermediate pin products within the second rail section than the corresponding angle of the grinding roller relative to the blanks within the first rail section.
It was found to be beneficial to use a grinding disc as an auxiliary roller in the second rail section. It is also possible, as shown in the disclosed embodiment, to employ the brush roller for the after treatment of the pin points. The invention thus eliminates the conventional separate deburring process for battery terminals. The available guiding of the pin blanks is used according to the invention simultaneously to finish the battery terminals in groups. Because the grinding of the pin points, on the one hand, and the deburring of the finished points, on the other hand, are performed simultaneously but separately in groups in neighboring rail sections on sequentially arranged pins, a considerable time saving is realized.
The invention is directed also to a device for performing the method according to claim 1. In the invention a device for grinding the pin points can take over the new function, mentioned already several times, of deburring the finished pin points. An extension of the transport rail is of no concern when the rail sections are positioned vertically staggered and the pins are guided in opposite directions in these sections in a switchback fashion. Accordingly, the device can be designed to have a size that is space-conserving.